About Us

📌 About This Service

apps.fredric18.uk is a free web utility hub independently developed and operated by Fredric18. From essential Korean-life calculators — minimum wage, social insurance, official age reckoning, and military discharge dates — to global tools like currency conversion, unit transformation, health metrics, and developer utilities, everything runs instantly in your browser with zero sign-up or installation required. All calculations are processed client-side, ensuring no personal data is transmitted externally.

🎯 Our Mission

We built this service so that whenever you need a quick calculation, you can rely on one trusted hub instead of digging through search results or installing multiple apps. Our core goal is to reflect accurate domestic regulations (Korean Labor Standards Act, Minimum Wage Act, National Health Insurance Act, Military Service Act, etc.) in every Korea-specific calculator, while keeping all tools fully accessible to international users.

🛠️ Available Utilities (32 Tools)

We currently offer 32 free utilities across 7 categories.

• —💰 Finance: Hourly Wage & Holiday Pay, Salary & Tax (4 Social Insurances), Currency Converter, Split Bill, Travel Expense Splitter
• —📐 Unit Conversion: Length, Weight, Temperature, Area, Volume, and Korean traditional units
• —🇰🇷 Korea-Specific: Age Calculator, Military Discharge, Lunar Calendar, D-Day Counter
• —🎨 Design: Color Picker & HEX/RGB/HSL Converter
• —⌨️ Developer Tools: Base64 Encoder/Decoder, JWT Token Decoder, Word & Character Counter
• —📚 Education: Periodic Table, Multiplication Table, Trigonometry, Linear Algebra, Number Systems, Sequences & Limits
• —💪 Health & Fitness: BMI Calculator, Heart Rate Zone, Fitness Guide, FMD Diet Wiki
• —🎲 Entertainment: Famous Quotes, Ladder Game, Dice Roller, Order Picker, Lucky Draw, Team Generator

🌐 Language Support

We officially support Korean (ko) and English (en). Korea-specific tools that rely on domestic law and cultural standards are fully accessible in English for foreign residents and global users, with an informational notice at the top of each tool page.

💡 How We Operate & Ad Disclosure

All tools are provided completely free of charge. Server and maintenance costs are covered through Google AdSense display advertising and affiliate partnerships with Coupang Partners, AliExpress, and Amazon Associates. Ads are placed minimally to avoid disrupting usability. Clicking affiliate links or making purchases through them may generate a small commission for us, at no additional cost to you.

👤 About the Operator

This service is developed and independently operated by Fredric18 ([email protected]), a software engineer based in Seoul, South Korea. Leveraging deep familiarity with Korean labor law, tax regulations, and administrative standards, we build every domestic calculator (hourly wage, social insurance, official age, military discharge) on verifiable legal foundations. Bug reports, feature requests, and copyright inquiries can be submitted via the Contact page or operator email, with responses within 2–5 business days.

📰 Our Sister Site

This service is closely integrated with our sister site https://news.fredric18.uk (Fredric18 News), where we publish in-depth usage guides, release notes, new-feature announcements, and updates on relevant legal and policy changes—in both Korean and English. When you have questions about a specific tool, the utility-guide category on the news site offers deeper reference material. Both sites are mutually linked for seamless navigation.

• —📌 Fredric18 News home: https://news.fredric18.uk
• —📚 In-depth utility guides & news articles (KO & EN)
• —🔔 Release notes and new-feature announcements
• —⚖️ Legal and policy change notices affecting our tools

⚖️ Legal Basis & Official Data Sources

Every calculator in this service is grounded in the latest laws, regulations, and official data from the following authorities. Any legal amendments are reflected promptly.

• —💼 Labor Standards Act & Minimum Wage Act (Ministry of Employment and Labor): https://www.moel.go.kr — Basis for hourly wage, weekly holiday pay, night/overtime premiums, and 4 major insurance calculations
• —🏥 National Health Insurance Service & National Pension Service: https://www.nhis.or.kr, https://www.nps.or.kr — Basis for health insurance, long-term care, and national pension rates
• —💰 National Tax Service (NTS) Simplified Withholding Table: https://www.nts.go.kr — Basis for income tax and local tax calculations
• —🎖️ Military Manpower Administration & Ministry of National Defense: https://www.mma.go.kr — Basis for discharge dates, promotion timelines, and social service durations
• —⚖️ Unified Age Reckoning Act (Civil Act & Basic Administrative Act amendments, effective 2023.06.28) — Basis for international age calculation
• —📅 Korea Astronomy and Space Science Institute (KASI) ephemeris: https://astro.kasi.re.kr — Basis for lunar calendar conversion, 24 solar terms, and 60 Gapja
• —📊 Real-time global FX rates (Open Exchange Rates API) — Basis for currency conversion
• —⚕️ WHO & Korean Society for the Study of Obesity (KSSO) diagnostic criteria — Basis for BMI calculator
• —💪 American College of Sports Medicine (ACSM) & International Sports Sciences Association (ISSA) guidelines — Basis for heart rate zones and fitness guide
• —🧪 IUPAC official chemical element data — Basis for the periodic table